Portugal heatwave, 2022 - Forensic analysis

The UN Global Assessment Report on Disaster Risk Reduction (GAR 2024) report presents 10 case studies, each one with a forensic risk analysis, which systematically examines and investigates the disasters to understand their causes and impacts, as well as the effectiveness of any mitigation measures.

Step 1 - Understanding the disaster DNA

What happened?

During the spring and summer of 2022, Portugal experienced more than four distinct heatwaves, the most severe of which ran from July 2 to July 18. This exceptional event killed almost 2,400 people and triggered several devastating forest fires. Mostly affected were older citizens living inland. They are often living alone and in houses not prepared for this kind of extreme heat.

The heatwave mainly impacted non-coastal inland areas of Portugal, where maximum air temperatures reached record highs at 30 meteorological stations. On July 14, the village of Pinhão in northern Portugal recorded a temperature of 47.0°C, the highest July temperature ever recorded in mainland Portugal.

The heatwave also led to widespread forest fires. In July 2023, more than 50,000 hectares burned, more than double the average amount for that month over the previous decade. The fires injured dozens of people, forced the evacuation of many more, and caused damage to property, agriculture and infrastructure. One pilot died during fire suppression efforts.

Exposure: Where was damage concentrated?

Heat-waves are common during summer on the Portuguese mainland, although the Atlantic Ocean moderates the intensity of the heat. The most affected regions are the inland areas in central and northeastern Portugal.

Wildfires are a regular occurrence in Portugal's forests, with over 18,000 fires per year and an average 107,000 hectares burned each year since 1980. These fires are influenced by factors such as climate, land use changes (including afforestation and rural abandonment), and socioeconomic conditions. Portugal's dense, abandoned forests are particularly susceptible to wildfires, especially in areas with sustained heat and unstable air conditions.

Most homes in Portugal are not well-prepared for extreme heat. According to the 2021 Census, 83 percent of houses lack air conditioning, for example. Under current climate conditions, buildings in Lisbon have the highest Overheating Degree Hours above 26°C (ODH26) values, signifying greater risks of overheating in the summer.

Vulnerability: Who was affected and why?

The precise number of deaths associated with the heatwave cannot be directly determined. It can only be estimated by comparing the expected number deaths within the same period had the heatwave not occurred. For the July 2 to 18, 2022 heatwave, an excess mortality of 1,380 deaths is estimated. When considering all summer heatwaves in 2022, this figure increases to more than 2,401 deaths. Most heatwave-related mortality in 2022 occurring among citizens older than 65, especially those over 85.

There is no disaggregated data regarding the regional impact of the heatwave from July 2 to 18, 2022. However, based on analysis of past heatwaves, the highest increases in mortality were observed in Portugal's inland areas. In these regions, the heatwave was more persistent, and the moderating effect of the sea on temperature was not felt. Despite warnings from health and civil protection authorities, the persistence of the heatwave in inland areas likely contributed to the mortality pattern, as these regions typically have older citizens, many of whom live alone and are isolated. Buildings in these areas were not well-prepared to cope with extreme heat, especially in rural areas. In addition, access to media information and proximity to healthcare facilities were less developed than in large urban coastal areas.

The heatwave also had significant economic impacts, particularly in agriculture, which accounts for more than 60 percent of drought-linked losses. From 1980 to 2023, these were worth about around €200 million each year. Climate-related economic losses in Portugal amounted to €764 million in 2022 alone, with projections indicating an increase in the future. Extreme weather events also have cascading effects on agricultural economics. Vulnerable sub-sectors include non-irrigated cereals (such as maize), fruit trees, perennials, tubers in regions with heavy precipitation extremes, and livestock reliant on green fodder.

Resilience: what factors limited the impacts?

The 2022 heatwave in Portugal highlights the importance of having "the right mindset" to prevent disasters. In developing its legal frameworks, Portugal has placed special emphasis on preventive strategies, aiming to make them more seamless with response operations and acknowledging the historical imbalance between the two. An example of this mindset is seen in Portugal's spatial planning and land-use policies, which integrate risk management to build resilience against heatwaves and other hazards. This case study also highlights the benefits of "good governance", a key factor in disaster avoidance.

A 2019 European Commission Peer Review report noted that "the Portuguese civil protection system is constantly looking for improvements", with a process in which "all actors are involved". This reflects a "shift in focus from response to prevention" with "awareness and willingness to fill the remaining gaps".

Following major heatwaves in 1981 and 1991, which caused an estimated excess mortality of about 1,900 and 1,000 deaths respectively, Portugal established the Ícaro heat-health warning system in 1999. Ícaro provides daily heat-related mortality predictions to heat-health action plan practitioners, who then issue protection recommendation based on these advisories. Ícaro's data complements meteorological information.

Portugal has implemented a National Risk Assessment, a National Strategy for Disaster Risk Reduction, adopted in 2018, a National Platform for Disaster Risk Reduction, and various sectoral mechanisms aimed at risk reduction. The 2004 Contingency Plan for Extreme Adverse Temperatures sets strategic guidelines for risk management and public communication, coordinated by the General Directorate for Heat, with specific roles for health and civil protection authorities. Measures include increasing risk information to vulnerable groups, reinforcing health and social care structures, and activating temporary acclimatized shelters.

The National Health Service (SNS) operates a contact centre (SNS 24) that provides guidance for non-emergency health problems. Information on heat protection is available on the SNS 24 website and many local government websites during heatwave alerts. Annually, the Health Ministry prepares a contingency plan for extreme temperatures to prevent adverse health impacts, providing timely information to local authorities for risk assessments and corrective measures.

Municipal and intermunicipal climate action plans also address the impacts of heatwaves. Schools follow guidelines for risk education, developed by the Civil Protection Authority, the General Directorate of Education, and the General Directorate of School Establishments. This reference document offers guidance and showcases best practices for teaching risk-related subjects.

Step 2- Future trends:

This section looks at key root causes or emerging issues identified above and provides a snapshot of potential 'business and usual' trends where action now could prevent or reduce disasters in the future.

People

• Portugal has one of the world's oldest populations in the world. Between 2011 and 2022, the percentage of people in Portugal aged 65 or over increased from 19.2 to 24.0 percent. People over 65 make up nearly 30 percent of Portugal's adults, and this figure is expected to rise to 59.9 percent by 2035.
• In Lisbon, annual heat-related death rates may increase from 5.4 to 6 per 100,000 people in 1980-1998, reaching from 8.5 to 12.1 by the 2020s. Without action, this number could potentially reach a maximum of 29.5 by the 2050s.

Planet

• By the end of the 21st century, Portugal could experience as many as 8-10 heatwaves each year. Under extreme climate scenarios, temperatures could rise by as much as 5°C by 2100, with the greatest increases expected in the northeastern interior regions.
• Rural areas cover more than 90 percent of Portugal's mainland territory, with forests being the dominant land cover. This widespread rural landscape makes nearly all of Portugal's mainland territory vulnerable to wildfire risk. The growing risk of wildfires in Portugal result from a combination of factors, including changing land-use and management practices, shifting vegetation cover, and climate change. From 1960 to 2021, Portugal's rural population decreased from 5.7 million to 3.4 million, or from 65 percent to 33 percent of the total population. This decline has reduced agricultural plots, which can act as fuel breaks, as well as managed forests, leading to the accumulation of fire prone vegetation around rural settlements. Additionally, rural land abandonment and the aging rural population have reduced the number of people available to help contain and suppress wildfires when they occur.

Prosperity

• The Portuguese agricultural sector is expected to face significant challenges from heatwaves, which are likely to reduce crop yields and animal productivity due to heat stress. This poses a threat to food security and economic stability.
• In southern Europe, potential crop yields could decline by more than 10 percent under a 2°C warming scenario. Climate change could further restrict the availability of water for irrigation, with yield declines of over 20 percent projected for all European Union countries. In Portugal, crop losses could reach up to 80 percent. Without market adjustments, grain maize production may become unviable in areas facing water scarcity and significant decreases in precipitation.

Step 3- Forensic learning

This section aims to encourage dialogue around the forensic analysis to foster improved decision making. The areas for consideration below are envisaged as an input to stimulate in-country discussion and action plan on future disaster prevention and enhanced disaster risk management.